DESCRIPTION: (Applicant's Abstract) This application is a competing renewal of a Research Scientist Award. The candidate is Richard A. Meisch, M.D., Ph.D. He is a professor in the Department of Psychiatry and Behavioral Sciences and has a cross appointment in the Department of Pharmacology (Medical School, University of Texas, Houston Health Science Center). Environment: He is a member of the Psychiatry Department's Substance Abuse Research Center, and has high quality colleagues with whom he collaborates. His laboratory occupies approximately 4,000 square feet and is equipped with control and test apparatus for 30 primate and 20 rat operant test chambers. Research Projects: The research proposed is, in part, an evolutionary extension of a long-term research program concerning orally delivered drugs as reinforcers. The proposed research is grouped into five projects: (1) establishment of orally delivered drugs as reinforcers, particularly the use of drug substitution procedures, (2) tests of proposed treatment medications on drug reinforced behavior, (3) choice between different drugs and doses, (4) choice between drugs and competing reinforcers, and (5) choice between drug combinations and other drug solutions. In all studies rhesus monkeys will be the subjects and all reinforcing drugs will be delivered orally. The candidate's immediate career goals are to continue and extend ongoing research and to better integrate drug self-administration studies with human and laboratory animal subjects. Long term career goals consist of further evolution of the current studies and the systematic co-ordination of laboratory animal and human drug self-administration projects. In addition, possible relationships between the outcomes of laboratory and clinical trial studies will be explored. Another long-term goal is to take advantage of the multi-year durability of oral drug self-administration in monkeys and use this feature to undertake select collaborative studies of the neuropharmacology of drug reinforcement. Research Career Development Program. The research career development consists of collaborating with other faculty on projects that are related to oral reinforcement in monkeys, such as human laboratory drug self-administration studies.